The specific aims of this study are to determine whether the administration of Lorenzo Oil to neurologically asymptomatic patients with X-linked adrenoleukodystrophy (X-ALD) will diminish frequency of subsequent neurological disability. To determine whether the oral administration of 4-phenylbutyrate (4PBA) ameliorates the abnormality of VLCFA metabolism in X-ALD patients. To bring to completion an on-going study to determine the effects of docosahexaenole (DHA) and arachidonic acid (AA) therapy inpatients with disorders of peroxisome biogenesis.